Room temperature luminescence and ferromagnetism from transition metal ions: Mn-, Co- and Ni-doped ZnS nanoparticles

Abstract

ZnS nanoparticles (NPs) and transition metal ions (TMIs) doped ZnS NPs were synthesized by the chemical precipitation method facile via aqueous CTAB micelles. The structural properties, crystallography, morphology, composition analysis, photoluminescence (PL), and magnetic properties of samples were characterized by Fourier transform infrared spectrum (FTIR), X-ray diffraction (XRD) analysis, Field emission scanning electron microscope (FESEM), Energy dispersive X-ray (EDX) spectroscopy, Fluorescence spectroscopy, and Vibrating sample magnetometer (VSM). All the synthesized NPs exhibited a cubic zinc-blende single-phase crystal structure with crystallite size in 2–8 nm range, which indicates the TMIs ions substituted the lattice site of Zn2+ ions, due to almost similar ionic radii of Zn2+ and TMIs (Mn2+, Co2+, and Ni2+), i.e., 0.074, 0.083, 0.069, and 0.065 nm, respectively. PL peak intensity enhanced with TMIs doping causes an excited state to the ZnS NPs, resulting in PL spectra turning into the visible region. ZnS NPs show mixed dominant diamagnetic and weak ferromagnetic behavior. TMIs ions doped ZnS NPs show the well-defined ferromagnetic behavior at room temperature (RT).